Shortly after receiving the Musical Fidelity X10-D tube buffer, I felt I needed to upgrade the other components.

When the tube buffer arrived, I took the opportunity to also swap out my speakers.  In an earlier post, I extolled the virtues of the Grafyx SP-10 loudspeakers I own.  I had previously swapped out, then sold, the Boston Acoustics A-150 speakers I had paid only $30 for.  I enjoyed them, but felt the bass was a bit constricted due to having refoamed the woofers.  The mids were also not as smooth as I would have liked.

The Grafyx SP-10W pair of speakers I bought circa 1982 have identical componentry to the SP-10 pair I bought back in 1978.  The cabinets differ: the older pair uses vinyl veneer, whereas the “W” designation put nicer moldings on the front and covered the whole thing in genuine walnut veneer.  The emblems were upgraded to cast bronze, and the grille cloth was black as opposed to what I’d call a dark chocolate brown.  I had rewired them with far better OFC wiring.  They look nice!

Yet, I always felt they were not as good sounding as the original pair I bought.  It was time to swap the pair, and see if I really noticed a difference again…and indeed, I have.

The tube buffer has its own charm (the full write-up is in Part 1 of this series), but this pair of speakers is, to me, much more musical.  It is like the tube buffer: the change is subtle, but noticeable.

I still feel the mylar dome tweeters could use some minor improvement.  In fact, there are some cloth dome versions still out there in the wild.  Since the voice coil unit can be removed and swapped between magnets, I may locate a pair of the cloth dome tweeters and try them in this system.

The bass might be a little smoother in this older pair, yet it still extends quite deeply.  That is the charm of the SP-10 when I first heard it against the Polk Audio Monitor 7: the bass just extended much deeper.  In the right room, you can get clean response down to 32Hz (a low “C” on the scale).

So, what are the differences that make me still prefer this older pair?

First of all, the midrange.  It always seemed as though the newer SP-10W set was a little brighter and had a little more boom to the bass; turns out that what I’m really hearing is a fuller midrange in this older pair.  And it really hits a nice sweet spot!  These are the pair that the old $ensible $ound magazine raved about.  What I notice is a nice, full sound to the system–it just seems to meld together nicely.  In the newer pair, it now seems like the sound was disjointed–highs, lows, but no full midrange that really glued the whole spectrum together.

In addition to that midrange, it seems as though this pair images the soundstage better.  Perhaps the enhanced midrange helps pinpoint the locations of the individual instruments.  Or, it could be the cabinet construction.  The speakers likely have the same or very similar internal dimensions, but the SP-10W is about 1-1/2″ wider across the front, while the cabinet depth may be about 1 inch less at the most.  Both pairs have the baffle board on which the tweeter is mounted, which places it flush with the speaker grille and eliminates diffraction.  The edges of the older pair are slightly beveled, where the SP-10W were squared off.  The tweeters are identical.

And speaking of the imaging, I still do notice some of the “vertical blind” effect if moving from side to side.  I blame this on the tweeter’s plastic enclosure–it is concave, with a disc and six supports over the top of it.  While I do not want to remove the protection this provides, I often wonder what a similar dome tweeter would do for the sound, or even a ring radiator.  Yet, changing the tweeter unit would alter the sound of the whole system, and would require crossover modifications.  More on that shortly.

The sound, in tandem with the tube buffer, really blooms.  I hear a fullness beyond the range of the left and right speakers, yet the focus of centered voices and instruments appear dead center–the proverbial “phantom center channel” sounds more solid than I ever remember hearing it.  Voices, especially those of alto-range female vocalists, sound superb, as do acoustic instruments like the piano, which seem to hover in space now.

I have often wondered why these two sets of speakers could sound so different.  Yes it’s subtle, but over time I start being fatigued by the newer SP-10W pair than I do the originals.  One issue I had with my older pair is that the tweeters gave out.  These shipped from Grafyx with the Philips AD-0162T8 tweeters.  Madisound Speaker Components used to stock these replacements for about $12 each, and I ended up purchasing the AD-1624T8, which was the identical tweeter but with ferrofluid cooling in the voice coil gap.  I wish now I had purchased the AD-0163T8 soft domes instead, or in addition, so I could experiment.

But why should the tweeters matter?  I have two theories regarding the change in sonics.  First, I thought that Grafyx may have wanted to add a little more “sizzle” to the line by goosing the lower and upper ranges by reducing the midrange slightly.  However, one other idea came to mind much earlier: the tweeter crosses over at a somewhat lower frequency, and I suspected that Grafyx may have changed the crossover point to reduce warranty claims or give the tweeters a longer life.  It’s a moot point at this stage, 30 years later, but those are the only two reasons I can think of for re-voicing the system.  I may at some point rebuild the crossovers with fresh capacitors, but I will also take note between the two systems to see if any of the values were changed on the crossover boards.

Until I get the Sequel IIs in the listening room, though, these older SP-10s are doing nicely.  I can’t help but recommend them highly, especially for the money.  You end up with a cabinet about the size of the Large Advent, but without the many downfalls of that speaker (including the Advents’ finicky “fried egg” tweeter, and the woofers with the fragile voice coils that are pretty much goners if they even think about bottoming out).  And these image far better than my Small Advents ever could.